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Model compare

GPT-4.1 vs GPT-5.1

The readout for GPT-4.1 and GPT-5.1, before the detailed comparison sheet.

Model A

GPT-4.1

OpenAI

Contender
vs

Model B

GPT-5.1

OpenAI

Leading

Key Takeaways

Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Decision read

GPT-5.1

GPT-5.1 has the higher weighted result; Model A / B score 17.3 to 82.7.

Evidence depth

113 data points

Includes 24 benchmark rows, 0 audit samples, and 10 provider examples.

Selection signal

Start with GPT-5.1

The charts below split 34 high-signal samples across speed, scores, and audit health.

Change comparison

Switch either side of this report to compare another model with the same LMSpeed data pipeline.

Select a different model to open a new comparison URL.

Comparison sheet

This report only uses LMSpeed data for GPT-4.1 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

Model compare
GPT-4.1
GPT-5.1
Overall leaderContenderLeading
Weighted overall score17.3 pts82.7 pts
Benchmark category leads1 categories5 categories
Operational advantagesFirst-token latencyCheapest input price, Average speed, Free providers, Provider coverage
Context window1.0M tokens400K tokens
Max output32.8K tokens128K tokens
Modalities

Input

ImageTextFile

Output

Text

Input

ImageTextFile

Output

Text
Features
Text inputImage inputFile inputText outputTool callingStructured outputsJSON mode
Text inputImage inputFile inputText outputTool callingStructured outputsJSON modeReasoning

The overall result weights benchmark capability categories at 80% and price, API speed/latency, and availability at 20%. Recent test volume does not affect the winner, and missing benchmark categories are excluded.

Model metadata

Model compare
GPT-4.1
GPT-5.1
DeveloperOpenAIOpenAI
ReleasedApr 2025Nov 2025
ParametersNo dataNo data
TokenizerGPTGPT
Knowledge cutoff2024-06-30No data
OpenRouter IDopenai/gpt-4.1openai/gpt-5.1
ReferencesNo dataNo data

When to choose each model

This report only uses LMSpeed data for GPT-4.1 and GPT-5.1: pricing, speed aggregates, third-party benchmark scores, and shared provider samples.

GPT-4.1

GPT-4.1 is stronger in benchmark categories (Knowledge) and operational dimensions (First-token latency).

GPT-5.1

GPT-5.1 is stronger in benchmark categories (Agents, Coding, Reasoning, Math, Instruction following) and operational dimensions (Cheapest input price, Average speed, Free providers, Provider coverage).

Benchmark score comparison

Third-party benchmark profile synced into LMSpeed; only metrics available for both models are shown.

Category performance

Compare benchmark category scores on a 0-100 scale. Select a category to inspect the gap.

Model A coverage
6 / 8
Model B coverage
7 / 8
Shared
6 shared categories

Avg. score

GPT-4.1

45.6

Avg. score

GPT-5.1

51.2

Agents

GPT-5.1 leads by 7.7

GPT-4.139.9
GPT-5.147.6

Coding

GPT-5.1 leads by 12.5

GPT-4.137
GPT-5.149.5

Reasoning

GPT-5.1 leads by 5.4

GPT-4.148.4
GPT-5.153.8

Knowledge

GPT-4.1 leads by 5.3

GPT-4.157
GPT-5.151.7

Math

GPT-5.1 leads by 4.4

GPT-4.149
GPT-5.153.4

Multilingual

No data

GPT-4.1-
GPT-5.1-

Multimodal

GPT-5.1

GPT-4.1-
GPT-5.148.8

Instruction following

GPT-5.1 leads by 11.4

GPT-4.142.1
GPT-5.153.5

Professional benchmark details

Metric-level scores with benchmark source, rank depth, confidence, error, and evaluation date where available.

Aggregatereported

BenchLM overall score

SourceGPT-4.1

GPT-4.1

46.0

Rank #92/110 · confidence 1 · eval date 2025-04-14

+21.0

GPT-5.1

winner

67.0

Rank #28/110 · confidence 3 · eval date 2025-11-13

Pricingverified

Input price

SourceGPT-4.1

GPT-4.1

$2.00/M

Rank #142/185 · confidence 4

+$0.750/M

GPT-5.1

winner

$1.25/M

Rank #122/185 · confidence 4

Pricingverified

Output price

SourceGPT-4.1

GPT-4.1

winner

$8.00/M

Rank #137/185 · confidence 4

+$2.00/M

GPT-5.1

$10.00/M

Rank #141/185 · confidence 4

Pricingverified

Blended price

SourceGPT-4.1

GPT-4.1

$3.50/M

Rank #144/185 · confidence 4

+$0.062/M

GPT-5.1

winner

$3.44/M

Rank #138/185 · confidence 4

Reasoningreported

AA-LCR

SourceGPT-4.1

GPT-4.1

64.3

Rank #76/106 · confidence 1 · eval date 2025-04-14

+12.4

GPT-5.1

winner

76.7

Rank #24/106 · confidence 3 · eval date 2025-11-13

Reasoningverified

GPQA

SourceGPT-4.1

GPT-4.1

66.6%

Rank #152/217 · confidence 4

+20.7%

GPT-5.1

winner

87.3%

Rank #52/217 · confidence 4

Reasoningverified

MMLU-Pro

SourceGPT-4.1

GPT-4.1

winner

80.6%

Rank #59/129 · confidence 4

+0.5%

GPT-5.1

80.1%

Rank #62/129 · confidence 4

Reasoningverified

HLE

SourceGPT-4.1

GPT-4.1

4.2%

Rank #175/214 · confidence 4

+24.3%

GPT-5.1

winner

28.5%

Rank #60/214 · confidence 4

Codingverified

LiveCodeBench

SourceGPT-4.1

GPT-4.1

45.7%

Rank #65/115 · confidence 4

+41.1%

GPT-5.1

winner

86.8%

Rank #4/115 · confidence 4

Codingreported

AA-SciCode

SourceGPT-4.1

GPT-4.1

38.1

Rank #83/113 · confidence 1 · eval date 2025-04-14

+5.2

GPT-5.1

winner

43.3

Rank #60/113 · confidence 3 · eval date 2025-11-13

Mathreported

FrontierMath v2 (Tiers 1-3)

SourceGPT-4.1

GPT-4.1

5.5

Rank #37/47 · confidence 1 · eval date 2025-04-14

+25.5

GPT-5.1

winner

31.0

Rank #19/47 · confidence 3 · eval date 2025-11-13

Mathreported

BenchLM Math score

SourceGPT-4.1

GPT-4.1

28.1

Rank #54/63 · confidence 1 · eval date 2025-04-14

+21.1

GPT-5.1

winner

49.2

Rank #37/63 · confidence 3 · eval date 2025-11-13

Knowledgereported

AA-Omniscience Hallucination Rate

SourceGPT-4.1

GPT-4.1

winner

93.3

Rank #4/106 · confidence 1 · eval date 2025-04-14

+41.4

GPT-5.1

51.9

Rank #74/106 · confidence 3 · eval date 2025-11-13

Knowledgereported

AA-Omniscience Accuracy

SourceGPT-4.1

GPT-4.1

27.8

Rank #61/106 · confidence 1 · eval date 2025-04-14

+9.9

GPT-5.1

winner

37.7

Rank #43/106 · confidence 3 · eval date 2025-11-13

Knowledgereported

AA-GPQA Diamond

SourceGPT-4.1

GPT-4.1

66.6

Rank #96/113 · confidence 1 · eval date 2025-04-14

+20.7

GPT-5.1

winner

87.3

Rank #49/113 · confidence 3 · eval date 2025-11-13

Knowledgereported

BenchLM Knowledge score

SourceGPT-4.1

GPT-4.1

54.1

Rank #66/82 · confidence 1 · eval date 2025-04-14

+10.3

GPT-5.1

winner

64.4

Rank #52/82 · confidence 3 · eval date 2025-11-13

Knowledgereported

AA-HLE

SourceGPT-4.1

GPT-4.1

4.2

Rank #102/114 · confidence 1 · eval date 2025-04-14

+24.3

GPT-5.1

winner

28.5

Rank #53/114 · confidence 3 · eval date 2025-11-13

Knowledgereported

Artificial Analysis Intelligence Index

SourceGPT-4.1

GPT-4.1

19.6

Rank #92/117 · confidence 1 · eval date 2025-04-14

+17.9

GPT-5.1

winner

37.5

Rank #58/117 · confidence 3 · eval date 2025-11-13

Multimodalreported

AA-MMMU-Pro

SourceGPT-4.1

GPT-4.1

61.2

Rank #59/68 · confidence 1 · eval date 2025-04-14

+14.3

GPT-5.1

winner

75.5

Rank #31/68 · confidence 3 · eval date 2025-11-13

Multimodalreported

Design Arena Website

SourceGPT-4.1

GPT-4.1

1050.0

Rank #70/78 · confidence 1 · eval date 2025-04-14

+152.0

GPT-5.1

winner

1202.0

Rank #49/78 · confidence 3 · eval date 2025-11-13

Instruction followingreported

BenchLM Instruction Following score

SourceGPT-4.1

GPT-4.1

72.0

Rank #45/51 · confidence 1 · eval date 2025-04-14

+17.1

GPT-5.1

winner

89.1

Rank #20/51 · confidence 3 · eval date 2025-11-13

Instruction followingreported

AA-IFBench

SourceGPT-4.1

GPT-4.1

43.0

Rank #62/84 · confidence 1 · eval date 2025-04-14

+29.9

GPT-5.1

winner

72.9

Rank #27/84 · confidence 3 · eval date 2025-11-13

Agentsreported

Gert Labs

SourceGPT-4.1

GPT-4.1

25.6

Rank #49/49 · confidence 1 · eval date 2025-04-14

+15.6

GPT-5.1

winner

41.2

Rank #34/49 · confidence 3 · eval date 2025-11-13

Agentsreported

τ²-bench results

SourceGPT-4.1

GPT-4.1

47.1

Rank #67/82 · confidence 1 · eval date 2025-04-14

+34.8

GPT-5.1

winner

81.9

Rank #53/82 · confidence 3 · eval date 2025-11-13

API audit comparison

Latest completed audits from shared providers, with four safety and integrity score groups plus report links.

Provider
GPT-4.1
GPT-5.1
No completed audits are available from shared providers yet.

Provider examples

Speed aggregates and input/output pricing share each provider row for real API selection and migration cost checks.

Provider
GPT-4.1
GPT-5.1
SWT-API120 tests

GPT-4.1

speed / latency

81 tok/s / 1822ms

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

BUZZ10 tests

GPT-4.1

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

137 tok/s / 3299ms

input / output

No data

ModelPool5 tests

GPT-4.1

speed / latency

79 tok/s / 2301ms

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

N1N5 tests

GPT-4.1

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

96 tok/s / 1862ms

input / output

No data

42公益站0 tests

GPT-4.1

speed / latency

N/A / N/A

input / output

No data

GPT-5.1

speed / latency

N/A / N/A

input / output

No data

兔子API

GPT-4.1

gpt-4.1

speed / latency

No data

input / output

$0/request

GPT-5.1

gpt-5.1-chat-latest

speed / latency

No data

input / output

$0/request

初叶🍂Furry API

GPT-4.1

gpt-4.1

speed / latency

No data

input / output

$0.050/request

GPT-5.1

gpt-5-1

speed / latency

No data

input / output

$0/request

Yun API

GPT-4.1

gpt-4.1-2025-04-14

speed / latency

No data

input / output

$0.274/M/$1.10/M

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0027/request

KFCV50

GPT-4.1

gpt-4.1

speed / latency

No data

input / output

$0.137/M/$0.548/M

GPT-5.1

gpt-5.1

speed / latency

No data

input / output

$0.0068/request

YUNWU API

GPT-4.1

gpt-4.1-2025-04-14

speed / latency

No data

input / output

$0.048/M/$0.192/M

GPT-5.1

gpt-5.1-chat-latest

speed / latency

No data

input / output

$0.030/M/$0.240/M

FAQ

Weighted outcome: GPT-5.1. Benchmark capability categories carry 80%, while price, API performance, and availability carry 20%.

Why is this comparison indexable?
It has 6 verifiable comparison points, and both models have pricing or benchmark data.
Are missing metrics invented?
No. Metrics without LMSpeed data are omitted from this report.

Rankings are based on community-submitted tests and periodic health probes. Advisory only, not official data.